1. Field of the Invention
This invention relates to an applicator roll for a labeling apparatus for paying out and applying self-adhesive labels, with which in each operating cycle a self-adhesive label in a dispensing position can be adhered to an object through a rolling action of the applicator roll, having a sleeve via which the applicator roll is rotatably mounted on a hub of the labeling apparatus, wherein the sleeve has two cylindrical jackets and is equipped with at least one profiled ring arranged between the cylindrical jackets and projecting radially outwardly beyond the cylindrical jackets.
2. Description of Related Art
An applicator roll and a labeling device of this type are known from EP-B-0 976 658. In the labeling apparatus each self-adhesive label is printed with data directly before it is dispensed. The ink used for the printing does not dry by evaporating but by penetrating the label material. In spite of the fast sequence of operations during the labeling of articles the lateral surface of the applicator roll must not come into contact with printed characters which are not yet dry. This is because the soft plastic material of the lateral surfaces tends to pick up ink without absorbing it. The consequence of this would be that when that part of the lateral surface moistened with ink next came into contact with a label or with the surface of the article to be labeled, it would leave ink there. The result of this would be that the print on the label would be smeared and rather unattractive streaks would appear on the printed labels. To prevent this from happening, the sleeve in the known labeling apparatus is provided with at least one profiled ring which projects radially outwardly beyond the cylindrical jackets. Since the profiled ring and the sleeve are made of a material which is harder than the cylindrical jacket and therefore repels ink, the printed data on the label is not smeared by the profiled ring. To simplify production the profiled ring is integrally formed with the sleeve. Possible materials for the sleeve and the profiled ring are in particular relatively hard plastic such as Teflon, whereas the preferred choice for the cylindrical jackets is a relatively soft material, particularly rubber or plastic.
The profiled ring of the sleeve is positioned advantageously (in the axial direction of the sleeve) at a point where the printing mechanism of the labeling apparatus does not print any data on the label and hence no printed data can be smeared. With a printing mechanism having an even number of digits (such as six or eight), such a position is at the exact center of the sleeve, meaning that a profiled ring set in exactly central position is advantageous. However, if the printing mechanism has an odd number of digits such as seven digits, it makes sense to shift the profiled ring somewhat out of center in the axial direction of the sleeve, so that its position coincides with a space between two printing bands. The labeling apparatuses then have to be supplied with applicator rolls specially adapted to the particular printing mechanism. The applicator rolls then have to be kept on stock and interchangeable not only for adaptation to the different printing mechanisms, but also for adaptation to label formats of different widths. This increases manufacturing costs as well as the cost of operating the labeling apparatus.
A further applicator roll of the art, which is known from EP 0 200 932 B1, can be adapted to the label format. To this end the cylindrical jackets are capable of being releasably and positively locked in a plurality of positions against axial shifting, by displacement on the axis and by insertion of spacing rings. However, this is costly in terms of manufacturing and operation.